Breen performed alongside George Wendt, Tim Kazurinsky and Jim Belushi in a series of Second City revues starting in 1979. He later moved to Los Angeles, where he was part of the ensemble on HBO’s satirical series “Not Necessarily the News.” Later he produced TV series including “Whose Line Is It Anyway?” and “The Wayne Brady Show.”

“Whose Line” performer Colin Mochrie tweeted that Breen was “one of the world’s best. Very funny, very caring, the loveliest of the loveliest.”